World of Warcraft: Forever was developed following the observation of several players of World of Warcraft Classic electing not to move on to "The Burning Crusade Classic" expansion, instead wanting to experience new content at the original Level 60 cap. The "Season of Discovery" expansion to Classic was also created as a means of seeing what could be done and added with the Vanilla level cap. According to World of Warcraft Classic lead designer Tim Jones, four main pillars guided the design philosophy for World of Warcraft: Forever:

• New additions had to be in the spirit of Classic as opposed to novelties (i.e. no Flying Mounts or Level Scaling); Azeroth remains dangerous; difficulty is derived from player preparation and cooperation as opposed to arbitrary difficulty
• New content should be available for all levels of play, and not all stories are about saving the world
• No level cap increase; leveling is only way to catch up
• Trying to stay aware of how quality-of-life changes can affect how players socially interact with one-another